Shortly after 7 a.m. on Wednesday, a gunman armed with a rifle opened fire on a GOP congressional baseball team practice in Alexandria, Virginia, injuring majority Majority House Whip Rep. Steve Scalise (R-LA) and as many as four others, in what law enforcement sources are calling a "deliberate attack" on the group of Republicans.

President Donald Trump has now responded to the attack, issuing a statement Wednesday morning:

The Vice President and I are aware of the shooting incident in Virginia and are monitoring developments closely. We are deeply saddened by this tragedy. Our thoughts and prayers are with the members of Congress, their staffs, Capitol Police, first responders, and all others affected.

The president also posted a statement on Twitter praising Scalise as a "true friend and patriot."

"Rep. Steve Scalise of Louisiana, a true friend and patriot, was badly injured but will fully recover. Our thoughts and prayers are with him," he wrote.

According to early reports, Scalise was shot in the hip and at one point was dragging himself across the infield, while multiple people were lying on the ground. Sen. Rand Paul says as many as 50-60 shots were fired, while others have estimated as many as 100. A total of five people were transported to the hospital, including Rep. Scalise.

Rep. Ron DeSantis said he was asked by a man who fits the description of the gunman, "Are those Republicans or Democrats out there practicing?"

Rep. Mo Brooks, who was "on deck" when the shooting began, described the harrowing situation to CNN: ​

Brooks said there were a number of congressmen and congressional staffers lying on the ground, and at least one of them was wounded. The Alabama Republican said he used his belt as a tourniquet to help one of the victims.

He said the shooter appeared to be a white male but added that "I saw him for a second or two." He said the shooter was behind the third base dugout and didn't say anything.

"The gun was a semiautomatic," Brooks said, adding that he was sure it was a rifle but unsure what kind. "It continued to fire at different people. You can imagine, all the people on the field scatter."

Michigan Rep. Mike Bishop gave an account of the event to WWJ Newsradio 950:

As we were standing here this morning, a gunman walked up to the fence line and just began to shoot. I was standing at home plate and he was in the third base line. He had a rifle that was clearly meant for the job of taking people out, multiple casualties, and he had several rounds and magazines that he kept unloading and reloading. ... The only reason why any of us walked out of this thing, by the grace of God, one of the folks here had a weapon to fire back and give us a moment to find cover. We were inside the backstop and if we didn’t have that cover by a brave person who stood up and took a shot themselves, we would not have gotten out of there and every one of us would have been hit — every single one of us. He was coming around the fence line and he was looking for all of us who had found cover in different spots. But if we didn’t have return fire right there, he would have come up to each one of us and shot us point-blank.

Alexandria Police Chief Michael Brown says that two Capitol Police officers engaged the shooter, who is now in custody, and that there is "no additional threat." The FBI is now on the scene investigating.